This invention relates generally to an insertion device for automatic placement of an insertion set through the skin of a patient, and in particular embodiments to a compact and easily operated insertion device for placement of an insertion needle of a subcutaneous insertion set or the like through the skin of a patient with a controlled force and insertion speed by the patient.
Medical needles are widely used in the course of patient care and treatment, particularly with respect to the delivery of selected medications to a patient. In one common form, hollow hypodermic needles are employed for transcutaneous delivery of a selected medication from a syringe or the like. In another common form, insertion needles are employed for transcutaneous placement of a soft and relatively flexible tubular cannula, followed by insertion needle removal and subsequent infusion of medical fluid to the patient through the cannula. More recently, insertion needles have also been used for transcutaneously placing other medical devices such as a subcutaneous sensor for monitoring specified patient parameters, such as blood glucose level.
In certain medical treatment regimens, it may be necessary or desirable for the patient to transcutaneously place the medical needle. For example, diabetic patients frequently self-administer insulin injections or periodically place a subcutaneous insertion with a cannula for subsequent programmable delivery of insulin by means of a medication infusion pump of the general type described in U.S. Pat. No. 4,685,903. Such subcutaneous insertion sets are disclosed, for example, in U.S. Pat. Nos. 4,755,173; 5,176,662; and 5,257,980 which are incorporated by reference herein. Diabetic patients may also use a subcutaneous insertion set to periodically place a transcutaneous glucose sensor wherein such sensor insertion sets are disclosed, for example, In U.S. Pat. Nos. 5,390,674; 5,568,806; 5,586,553, which are also incorporated by reference herein.
Some patients are reluctant or hesitant to pierce their own skin with a medical needle, and thus encounter difficulties in correct needle placement for proper administration of the medication. Such difficulties can be attributable to insufficient manual dexterity or skill to achieve proper needle placement or, alternately to, anxiety associated with anticipated discomfort as the needle pierces the skin. This problem can be especially significant with medications delivered via a subcutaneous flexible insertion set, since incorrect placement can cause kinking of the cannula and resultant obstruction of medication flow to the patient. Cannula kinking can be due to insertion set placement at an incorrect angle relative to the patient""s skin, and/or needle placement with an incorrect force and speed of insertion.
The present invention relates to an automatic injector, particularly for use with a subcutaneous insertion set, for quickly and easily placing an insertion needle through the skin of a patient at the correct insertion angle, and with a speed and force of insertion which minimizes patient discomfort.
It is an object of an embodiment of the present invention to provide an improved insertion device and insertion set, which obviates for practical purposes, the above mentioned limitations.
According to an embodiment of the invention, an injector is provided for quick and easy transcutaneous placement of a medical needle through the skin of a patient, particularly such as an insertion of a subcutaneous insertion set. The injector is designed to place the needle through the skin at a selected insertion angle and with a controlled force and speed of insertion, to ensure proper needle placement with minimal patient discomfort. The injector is particularly designed to meet these objectives, while safeguarding against undesired projection of the medical needle through free space, in the event that the injector is actuated in spaced relation to the patient""s skin.
The injector comprises a spring-loaded plunger having a head for receiving and supporting an insertion set in a position with an insertion projecting outwardly for transcutaneous placement through the skin of a patient. The plunger is designed for retraction and retention within a barrel to a cocked position with a drive spring compressed in a manner applying a predetermined spring force to the plunger head. A front or nose end of the injector barrel is designed for pressed placement against the skin of a patient, at a selected needle insertion site, and in an orientation with the needle disposed at a correct or desired insertion angle. A trigger member is operable to release the plunger and thereby permit the drive spring to carry the insertion set toward the patient""s skin with a controlled force and speed, resulting in proper transcutaneous placement of the insertion needle with minimal patient discomfort.
The plunger head includes a safety lock mechanism to retain the insertion set against projection from the injector barrel. In one preferred form, the safety lock mechanism comprises at least one and preferably a pair of safety lock arms for engaging and retaining the insertion set when the plunger is retracted from a fully advanced position. Each safety lock arm includes a cam lobe for engaging an appropriately shaped recess on the insertion set to prevent release thereof from the plunger head, unless and until the plunger head is returned to the fully advanced position. In such fully advanced position, the shape of the cam lobe permits quick and easy separation of the injector from the insertion set with a minimal separation force.
In operation, the safety lock arms thus prevent projection of the insertion set from the injector, in the event that the trigger member is actuated with the nose end of the barrel spaced from the skin of a patient. In that event, the plunger head is advanced with the controlled force and speed to the fully advanced position, but the insertion set is not thrown from the injector as a projectile. Instead, the insertion set travels rapidly with the plunger head to the fully advanced position, whereat the injector can be separated with minimal separation force from the insertion set.
In an alternative preferred form, the safety lock mechanism comprises a plunger head having a cylindrical shape defining a forwardly open cavity for receiving and supporting an insertion set with the insertion needle and cannula projecting outwardly. In this embodiment, the plunger head includes a radially inwardly projecting rim at a forward or nose end thereof, wherein the rim defines an oval-shaped opening. The size of the rim opening permits relatively free reception of a hub on the insertion set, with the infusion set oriented at an angle relative to a central axis of the plunger head and barrel. The insertion set is then reoriented to align the insertion needle coaxially with the central axis of the barrel and plunger head, so that the rim is received into a recess on the insertion set and functions to retain the infusion set against undesired release from the injector during spring-driven placement of the needle. After needle placement, the injector is released from the insertion set with minimal separation force by orienting the injector angularly relative to the insertion set to permit free slide out passage of the hub through the oval rim opening.
In a further alternative form of the invention, the plunger head is shaped to define a laterally open undercut slot sized for relatively free slide-fit reception of the needle hub of the insertion set. In this version, the insertion set is assembled quickly and easily with the plunger head of the injector by laterally sliding the hub into the laterally open slot, thereby orienting the medical needle generally coaxially relative to the central axis of the injector barrel and plunger head. In this position, the plunger head can be retracted and locked, followed by appropriate trigger member release for transcutaneously placing the medical insertion needle. After the needle is placed on the patient, the injector can be disassembled from the insertion set by laterally sliding the injector relative to the needle hub. Alternatively, the injector can be withdrawn or retracted from the patient""s skin to slidably separate the needle from the insertion set which remains in place on the patient""s skin.
In other embodiments of the present invention, an insertion device for inserting at least a portion of at least one piercing member of an insertion set through the skin of a patient includes a device housing, a carrier body and a driver. The carrier body is slidably received within the device housing for movement between an advanced position and a retracted position. The carrier body also includes a receiving structure to support the insertion set in a position with the at least one piercing member oriented for insertion through the skin of the patient at a predetermined angle relative to the skin of the patient upon movement of the carrier body from the retracted position to the advanced position. The driver is operatively coupled between the device housing and the carrier body to urge the carrier body with a controlled force and speed from the retracted position toward the advanced position to place at least a portion of the at least one piercing member of the insertion set thorough the skin of the patient to install the insertion set to the patient. The receiving structure of the carrier body is removable from the insertion set while maintaining the installation of the insertion set to the patient.
In particular embodiments, the predetermined angle relative to the skin is about 90 degrees, between 90 degrees and 10 degrees, or is after insertion between 0 and 10 degrees. In additional embodiments, the insertion set is a transcutaneous insertion set, a subcutaneous insertion set, an infusion set, sensor set or the like. In still other embodiments, the insertion set rests mainly on the surface of the skin after insertion or the insertion set is implanted in the skin of the patient. In preferred embodiments, the at least one piercing member is a needle. In alternative embodiments, the at least one piercing member is a plurality of needles, and can also be a plurality of micro-needles. Also, in some embodiments, the insertion set insertion set can be both an infusion set and a sensor set combined into an integral unit.
In yet other embodiments the insertion device, the device housing has a forward end defining a generally planar angled insertion contact surface for placement against the skin of a patient with the device housing in a predetermined orientation relative to the patient""s skin that mirrors the predetermined angle relative to the skin of the patient. Other embodiments include a trigger mechanism that actuates the driver. For instance, the trigger mechanism includes at least one trigger for fingertip depression to actuate the driver for movement of the carrier body from the retracted position to the advanced position. In addition, the driver can include at least one spring for spring-loaded movement of the carrier body from the retracted position to the advanced position. Further, the driver can include a force changing mechanism that permits alteration of the controlled force and speed of the carrier body moving from the retracted position to the advanced position from one insertion cycle to another insertion cycle. In still further embodiments, the device housing and the carrier body include a cooperatively engageable track mechanism for guiding movement of the carrier body between the advanced and retracted positions while retaining the carrier body against rotation relative to the device housing.
In additional embodiments of the insertion device, the at least one piercing member is provided with a piercing member hub as part of the insertion set. In addition, the receiving structure of the carrier body includes a recess formed therein for mated slide-fit reception of the piercing member hub of the insertion set. Further, the recess of the receiving structure can include a laterally open undercut recess. Alternatively, the receiving structure may include a safety retainer structure that retains the at least one piercing member on the receiving structure during movement from the retracted position to the advanced position. This safety retainer structure permits separation of the at least one piercing member from the carrier body when the carrier body is in the advanced position.
Yet another embodiment of the present invention is directed to an insertion set for insertion through the skin of a patient by an insertion device. The insertion device has a slidable carrier body for movement between an advanced position and a retracted position. The carrier body of the insertion device including a receiving structure to support the insertion set in a position for insertion through the skin of the patient upon movement of the carrier body from the retracted position to the advanced position. The insertion device also having a driver operatively coupled to the carrier body that urges the carrier body with a controlled force and speed from the retracted position toward the advanced position for insertion of the insertion set thorough the skin of the patient. The insertion set includes at least one piercing member and a set housing. The at least one piercing member includes a portion of the at least one piercing member that is insertable through the skin of the patient. The set housing is coupled to the at least one piercing member. Also, the set housing is shaped to fit within the carrier body of the insertion device to orient the at least one piercing member for placement through the skin of the patient of at least a portion of the at least one piercing member at a predetermined angle relative to the skin of the patient to install the insertion set to the patient. The set housing of the insertion set is removable from the receiving structure of the carrier body while maintaining the installation of the insertion set to the patient.
In particular embodiments of the insertion set, the predetermined angle relative to the skin is about 90 degrees, between 90 degrees and 10 degrees, or is after insertion between 0 and 10 degrees. In additional embodiments, the insertion set is a transcutaneous insertion set, a subcutaneous insertion set, an infusion set, sensor set or the like. In still other embodiments, the insertion set rests mainly on the surface of the skin after insertion or the insertion set is implanted in the skin of the patient. In preferred embodiments, the at least one piercing member is a needle. In alternative embodiments, the at least one piercing member is a plurality of needles, and can also be a plurality of micro-needles. Also, in some embodiments, the insertion set can be both an infusion set and a sensor set combined into an integral unit.
In other embodiments of the present invention, an insertion device for inserting at least a portion of at least one piercing member of an insertion set through the skin of a patient includes a device housing with an angled end, a carrier body and a driver. The device housing includes an angled end of the housing device to support a selectable insertion angle of the insertion device relative to the skin of the patient. The carrier body is slidably received within the device housing for movement between an advanced position and a retracted position. The carrier body also includes a receiving structure to support the insertion set in a position with at least one piercing member oriented for insertion through the skin of the patient at the selectable insertion angle relative to the skin of the patient upon movement of the carrier body from the retracted position to the advanced position. The driver is operatively coupled between the device housing and the carrier body to urge the carrier body from the retracted position toward the advanced position to place at least a portion of the at least one piercing member of the insertion set through the skin of the patient to install the insertion set to the patient. The receiving structure of the carrier body is removable from the insertion set while maintaining the installation of the insertion set to the patient.
In particular embodiments, a portion of the angled end includes a multi-planar surface to facilitate the selection of selectable insertion angle. In additional embodiments, the angled end is a separate-rotatable member connected to the device housing by at least one pin to facilitate the movement of the device housing about the separate-rotatable member and support the selectable insertion angle of the insertion device. In other embodiments, the separate-rotatable member of the device housing includes a contact surface to provide a substantially flat contact surface for the insertion device against the patient""s skin.
In additional embodiments, the piercing-member insertion angle is from 20 degrees to 45 degrees, or is between 0 and 20. In other embodiments, a portion of the angled end forms a curved opening with two arms surrounding the receiving structure, and the two arms extend beyond the receiving structure of the carrier body to support the device housing at the selectable insertion angle of the insertion device. In other embodiments, the receiving structure has a skin contacting surface with a multi-planar front end. The multi-planar front end of the receiving structure is shaped to be co-extensive with the angled end of the device housing when the carrier body is in the advanced position to facilitate insertion at the selectable insertion angle of the device housing relative to the patient""s skin.
In yet other embodiments, the receiving structure may include a locking mechanism to engage at least a portion of the insertion set. In addition, the locking mechanism may include teeth which are coupled to the insertion set and secured in position by a spring member to facilitate locking and placement of the piercing member at the selectable insertion angle of the device housing relative to the patient""s skin.
In yet still other embodiments, the selectable insertion angle relative to the skin is about 90 degrees, between 90 degrees and 10 degrees, or after insertion is greater than 0 and less than or equal to 10 degrees. In additional embodiments, the insertion set is a transcutaneous insertion set, a subcutaneous insertion set, rests mainly on the surface of the skin after insertion, or is fully implanted in the skin of the patient. In preferred embodiments, the at least one piercing member is a needle. In alternative embodiments, the at least one piercing member is at least one needle or a micro-needle. In some embodiments, the insertion set is an infusion set or a sensor set. In other embodiments, the insertion device includes a trigger mechanism that actuates the driver.
Another embodiment of the present invention is for an insertion device for inserting at least a portion of at least one piercing member of an insertion set through the skin of a patient includes a device housing, a carrier body, a locking mechanism and a driver. The device housing supports the insertion device relative to the skin of the patient. The carrier body is slidably received within the device housing for movement between an advanced position and a retracted position. The carrier body includes a receiving structure to support the insertion set in a position with at least one piercing member oriented for insertion through the skin of the patient upon movement of the carrier body from the retracted position to the advanced position. The locking mechanism is included to engage at least a portion of an insertion set and secure it to the receiving structure of the carrier body, and to substantially prevent the premature release of the carrier body before securing it in position against the patient""s skin. The driver is operatively coupled between the device housing and the carrier body to urge the carrier body from the retracted position toward the advanced position to place at least a portion of the at least one piercing member of the insertion set through the skin of the patient to install the insertion set to the patient. Also, the receiving structure of the carrier body is removable from the insertion set while maintaining the installation of the insertion set to the patient. In particular embodiments, the locking mechanism includes a lever arm coupled with teeth to secure the insertion set to the receiving end of the carrier body and a spring coupled between the lever arm and the receiving end of the carrier body to bias the lever arm in a locking position and facilitate the placement of the piercing member in the patient""s skin.
In further embodiments of the present invention an insertion device for inserting at least a portion of at least one piercing member of an insertion set through the skin of a patient includes a device housing, a carrier body, and a driver. The device housing supports the insertion device relative to the skin of the patient. The carrier body is slidably received within the device housing for movement between an advanced position and a retracted position. The carrier body also includes a receiving structure to support the insertion set in a position with at least one piercing member oriented for insertion through the skin of the patient upon movement of the carrier body from the retracted position to the advanced position. The driver is operatively coupled between the device housing and the carrier body to move the carrier body from the retracted position toward the advanced position to place at least a portion of the at least one piercing member of the insertion set through the skin of the patient to install the insertion set to the patient. Further, the receiving structure of the carrier body is removable from the insertion set while maintaining the installation of the insertion set to the patient.
In particular embodiments, the carrier body is a plunger to hold the insertion set and to insert it in the patient""s skin by moving from the retracted position to the advanced position. Also in other embodiments, the carrier body is operatively coupled to a detent within the device housing. The detent has a threshold force level that must be overcome to permit and to facilitate the movement of the plunger from the retracted position to the advanced position with a controlled force and speed. In additional embodiments, the distance traveled by the plunger within the device housing is equal to at least a distance required to fully insert the insertion set in the patient""s skin that is at least equal to an implantable length of the piercing member. Additionally, the carrier body may be adapted for use with different types of insertion sets.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, various features of embodiments of the invention.